Cannot Attach or Upload Files

Hi all - I upgraded recently to Mojave 10.14.6 and since then I am unable to attach or select any files for upload, regardless of the app or online program I am using. I use Constant Contact for work and when I select "Upload Image" for example, nothing happens. I cannot drag or drop either. I cannot attach files to Gmail when selecting the paper clip and I get error codes ("Invalid") for other programs. I cleaned up a TON of space on my hard drive, emptied trash, removed icons and shortcuts on my desktop, rebooted, clean up temp files and nothing has worked. I am using Safari primarily and I tried Chrome - same happens with either browser.

Please help!

Thx

~B